Electrically actuated punch press

ABSTRACT

A solenoid having an axially movable armature is coupled to and arranged to displace the movable member of a punch press. A plurality of different tools may be clamped to an anvil and tool holder of the punch press for either assembly line or work bench type of production. The apparatus is small and relatively light in weight. The solenoid may have resin encapsulated, coiled aluminum foil strips instead of the more conventional wire wound coil.

United States Patent n91 Doherty 1 Jan. 9, 1973 [541 ELECTRICALLY ACTUATED PUNCH 2,155,578 4/1939 Anderson ..s3/s77 x PRESS 2,509,956 5/1950 Benoit ..83/577 2, 39,902 1 1951 F l ..83 577X [76] Inventor: Norman R. Doherty, 870 Main 5 I o ey I Street, Farmlngdale, NY. 11735 Primary Examiner prank T Yost [22] Filed: March 18, 1971 Attorney-Leonard 1-1. King [21] Appl. No.: 125,484 [57] ABSTRACT A solenoid having an axially movable armature is cou- [52] US. Cl. ..83/575, 782;;16330i8833Z56898 pled to and arranged to displace the movable member [51 I t Cl B26d 5/08 of a punch press. A plurality of different tools may be d 588 637 clamped to an anvil and too] holder of the punch press 0 3l8/1l9 5 5 6 for either assembly line or work bench type of production. The apparatus is small and relatively light in weight. The solenoid may have resin encapsulated, [56] References Cited coiled aluminum foil strips instead of the more con- UNITED STATES PATENTS ventional wire wound coil.

1,684,296 9/1928 Rodsky ..83/577 X 12 Claims, 6 Drawing Figures PATENTEDJAH 9 I975 SHEET 1 BF 3 Fig. l

mvsmon. Norman R. Doherty I md HJi ATTORNEY PATENTEDJAM 9197s SHEET 2 [1F 3 iiwmozz Norman R. Doherty ATTORNEY PATENTEDJAN 9l975 3.709.083

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. mvENTbR. Norman R. Doherty BY a I A d; Fag. 2

ATTORNEY ELECTRICALLY ACTUATED PUNCH PRESS The aforementioned Abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to power tools and more particularly to an electrically actuated punch press.

2. Description of the Prior Art There is a long standing need for a low cost, small sized punch press. While there are many punch presses presently on the market, these devices are generally large and cumbersome. The most common devices in the prior art are those punch presses that are operated by means of a fly wheel or by hydraulic pressure requiring a source of compressed air. More specifically the need exists for a small, high capacity die set or punch press that can be operated on a bench, particularly for performing small stamping and assembly operations.

SUMMARY OF THE INVENTION The present invention fills the void in the prior art by providing a low cost, small sized punch press that is electrically actuated. A standard die set, for example, the type that is commercially available and sold by the Acme Danneman Company, Inc. of New York, is utilized in the present invention. The die set is typical of sets used in small power and foot presses and comprises a base member or die shoe having an anvil and precisely positioned leader pins and a head member or tool holder that is opposed to the anvil and which slides on bushings that are slipped over the leader pins. Since the die set assemblies that are commercially available are made in mass production, they are relatively low in cost and have the additional advantage of interchangeable parts.

The power source for the present invention is in the form of an improved solenoid that is coupled to and arranged to periodically displace the movable member or tool holder of the die set. The solenoid acts substantially faster than was possible with the prior art power sources and therefore minimizes bending forces on the leader pins so that relative lightweight components may be utilized. In one form of the invention the solenoid is wound with an aluminum foil coil in place of the more conventional wire wound coil of the prior art. Insulation means are used between the adjacent turns of the aluminum foil winding.

Accordingly, it is an object of the present invention to provide an improved punch press.

It is another object of the present invention to provide an improved, electrically actuated punch press.

An important object of the present invention is to provide an improved, electrically actuated punch press that is low in cost, small in size.

A further object of the present invention is to provide an improved solenoid for an electrically actuated punch press as described above.

Still another object of the present invention is to provide an improved solenoid for a punch press or the like, the solenoid having an aluminum foil winding.

These and other objects, features and advantages of the invention will, in part, be pointed out with particularity and will, in part, become obvious from the following more de-tailed description of the invention, taken in conjunction with the accompanying drawing, which forms an integral part thereof.

BRIEF DESCRIPTION OF THE DRAWING In the various figures of the drawing like reference characters designate like parts.

In the drawing:

FIG. 1 is a front elevational view of the present invention, partially broken away and partially in section;

FIG. 2 is a sectional elevational view taken along line 2-2 of FIG. 1;

FIG. 3 is a plan view of the present invention;

FIG. 4 is a sectional plan view taken along line 44 of FIG. 1',

FIG. 5 is a schematic, electrical wiring diagram of a winding and terminal arrangement that may be used with the solenoid of the present invention; and

FIG. 6 is another electrical wiring diagram illustrating an alternative winding and terminal arrangement of the solenoid comprising the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, there is shown an improved, electrically actuated punch press 10 comprising the present invention. The punch press 10 includes a base member or die shoe generally designated by the reference character 12. The die shoe 12 is comprised of a base plate 14 to which is secured an anvil holder 16. Screws 18 are used for this purpose. Slots 19 formed in the base plate 14 are used for removably mounting the punch press 10 on a workbench. The anvil holder 16 has a counterbored hole 20 that is adapted to receive a screw 22 and the shank portion of an anvil 24. The screw 22 secures the anvil 24 to the anvil holder 16. It should be noted that the anvil 24 may be in the form of a punch, a forming tool or any other configuration that meets the requirement of the particular operation.

A pair of bushings 26 are mounted in suitably sized and placed openings in the die shoe 12 in order to receive a pair of leader pins 28. Pins 30 are used for securing the leader pins 28 to the die shoe 12. Resilient shock absorbers or bumpers 32 are mounted on top of the bushings 26 and about the leader pins 28 in order to cushion the downward force of punch press.

The movable portion or tool holder of the punch press 10 comprising the present invention is generally designated by the reference character 34. A tool 36, such as a hammer or the like, is mounted in a bore 38 formed in the tool holder 34 and is secured thereto by means of screws 40. The upper end of the tool 36 is provided with a concave seat 42 for purposes to be described hereinafter.

Openings 44 formed in the tool holder 34 are sized and positioned so as to receive bushings 46 which are mounted on the leader pins 28 for sliding movement relative thereto. A resilient shock absorber or bumper 48 is positioned at the upper end of each of the bushings 46 and about the leader pins 28 so as to cushion the upward force of the punch press 10. Finally, the punch holder 34 is provided with a pair of axially extending openings 50 whose function will be described subse-quently.

A two-part housing generally designated by the reference character 52 is provided at the upper end of the punch press 10. The two-part housing 52 is comprised of an upper section 54 and a lower section 56 both of which may be metal castings. A guide sleeve 58 is positioned about the upper end of each of the leader pins 28, the sleeve 58 extending through coaxial bores 60 formed in the upper and lower housing sections 54 and 56. Screws 62 are used to secure the two housing sections 54 and 56 to each other. A plate 64 is positioned above the top of the upper housing 54 and is secured thereto by means of screws 66. Screws 68 capture the housing 52 to the leader pins 28 in order to provide additional rigidity.

An upper, threaded stud 70 and a lower, threaded stud 72 are secured to each sleeve 58 and its associated bushing 46, respectively. The outer ends of the studs 70 and 72 include reduced diameters or annular grooves that provide means for anchoring compression springs 76. It will be noted, particularly in FIG. 1, that the springs 76 extend through the openings 50 formed in the punch holder 34. The lower housing half 56 is provided with a counterbored, centrally located hole 78 in which is positioned a guide bushing 80 in a force fit.

A solenoid generally designated by the reference character 82 is positioned in the housing 52 as shown, for example, in FIG. 2. In the embodiment illustrated, the solenoid 82 is comprised of an aluminum foil winding 84 that has insulating material positioned between adjacent turns. The aluminum foil winding 84 is encapsulated in an epoxy resin material 86. An annular rim 88 of the epoxy material 86 is received in an annular recess or groove 90 formed in the lower housing half 56 in order to key the solenoid 82 to the housing 52. The remainder of the epoxy material 86 is positioned within a recess 92 formed in both housing halves 54 and 56. A plug member connected to the winding 84 may be partially encapsulated in the resin.

An armature generally designated by the reference character 94 is slidable relative to the aluminum foil winding 84. The armature 94 is comprised of a shaft portion 96 that passes through the bushing 80 in the lower housing half 56. The shaft 96 has a spherical end 98 which is received in the concave recess 42 formed at the top of the tool holder 36. The opposite end of the armature 94 is in the form of an enlarged head portion 100.

As shown particularly in FIG. 2, the head portion 100 is provided with a central bore 102 at the upper end thereof. A pin 104 extends transversely through the head portion 100 and through the bore 102. A compression spring 106 has one of its ends secured to the pin 104 and has its opposite end secured in any suitable manner to a cap 108, such as by means ofa screw 110. The cap 108 is secured to the upper housing half 54 by means of screws 112. Resilient shock absorbers in the form of washers 114 and 116 are positioned about the head portion 100 of the armature 94 in order to provide cushioning means for the armature 94 at the upper end of its strike. An O ring 118 is received in an annular groove at the upper end of the head portion 100 of the solenoid armature 94 and forms a seal together with the internal wall of the hollow housing 52. A lateral extension 120 is formed in the two housing halves 54 and 56 in order to provide an enclosure for terminal means 122 ofthe solenoid 82.

A preferred circuit is shown in FIGS. 5 and 6 wherein winding 65 is shown with end taps 67 and 71 and center tap 69. Cable 73 is arranged to connect the winding to a 220V source. On the other hand, in FIG. 6 there is shown cable with provision to connect end taps 67 and 71 together to one leg ofa 1 10V circuit. Thus a single winding can be used optionally on 1 10V or 220V. it is contemplated that the solenoid be energized from a circuit which can provide a predetermined number of cycles of power or even a fraction of a cycle if desired.

When the solenoid 82 is energized by a suitable source of electricity, the armature 94 will drive the tool holder 34 and the tool 36 in a downward direction against the workpiece that is resting on the anvil 24. The bushings 46 will slide downwardly along the leader pins 28. During this portion of the operating cycle the springs 76 and 106 will be extended. Springs 76 serve to return the tool holder 34 to its initial, upper position when the solenoid 82 is de-energized. Spring 106 serves to pull the armature 94 upwardly to its initial position when the solenoid 82 is de-energized.

From the foregoing it will be evident that an improved, low cost punch press has been provided. The punch press is small enough to be used in assembly line production or on a work bench, for example, in a model shop. Different tools may be readily clamped to both the anvil and the tool holder. Because of its high rate of operation, the present invention avoids bending of the leader pins as was quite prevalent in the prior art wherein hydraulic actuating means were utilized. With the present invention it is possible to punch a threeeighths-inch diameter hole in three-sixteenths-inch thick stock of aluminum material with a 10-inch high press.

The present invention permits operating the device on either l 10 volts or 220 volts by the use of the proper connector plug since the termination of the coil is brought out to different terminals. The improved solenoid comprising the present invention, preferably uses a coil formed of aluminum foil that is wound with insultating material interleaved. However, it should be clearly understood that a wire wound coil may be used instead.

There has been disclosed heretofore the best embodiments of the invention presently contemplated. However, it is to be understood that various changes and modifications may be made thereto without departing from the spirit of the invention.

What I claim as new and desire to secure by Letters Patent is:

1. An electrically actuated punch press comprising:

a. a die shoe having an anvil mounted thereon;

b. a plurality of leader pins extending from said die shoe;

c. a tool holder slidably mounted on said leader pins, said tool holder being in opposition to said anvil;

d. spring means for normally urging said tool holder in a direction away from said anvil;

e. a solenoid having a wound coil and an armature linearly movable through said coil, said armature engaging said tool holder when said solenoid is energized thereby driving said tool holder in a direction towards said anvil; and

f. means for moving said armature in a direction away from said anvil when said solenoid is de-energized.

2. The punch press in accordance with claim 1 wherein said solenoid is contained within a housing and wherein there is further included means for coupling said housing directly to said leader pins.

3. The punch press in accordance with claim 1 wherein there is further included bushing means in said tool holder for slidably receiving said leader pins.

4. The punch press in accordance with claim 1 wherein there is further included resilient bumper means on said leader pins for cushioning said punch holder at the end of its stroke when said solenoid is energized.

5. The punch press in accordance with claim 1 wherein there is further included resilient bumper means on said leader pins for cushioning said punch holder at the end of its stroke when said solenoid is deenergized.

6. The punch press in accordance with claim 1 wherein said wound solenoid coil comprises a length of aluminum foil and there is further included a layer of electrical insulation between adjacent turns of said winding.

7. The punch press in accordance with claim 1 wherein said tool holder includes a concave seat, said armature having a spherical end portion in engagement with said seat;

8. The punch press in accordance with claim 2 wherein there is further included resilient bumper means intermediate said armature and said housing.

9. The punch pressin accordance with claim 2 wherein said means for moving said armature comprises spring means extending between said housing and said armature.

10. The punch press in accordance with claim 9 wherein there is further included a pin extending through said armature, one end of said spring means being coupled to said pin, said housing including a cap and means for securing said cap to said housing, the other end of said spring means being secured to said cap.

11. The punch press in accordance with claim 2 wherein said solenoid coil is encapsulated in an epoxy resin.

12. The punch press in accordance with claim 11 wherein said encapsulated coil is keyed to said housing. 

1. An electrically actuated punch press comprising: a. a die shoe having an anvil mounted thereon; b. a plurality of leader pins extending from said die shoe; c. a tool holder slidably mounted on said leader pins, said tool holder being in opposition to said anvil; d. spring means for normally urging said tool holder in a direction away from said anvil; e. a solenoid having a wound coil and an armature linearly movable through said coil, said armature engaging said tool holder when said solenoid is energized thereby driving said tool holder in a direction towards said anvil; and f. means for moving said armature in a direction away from said anvil when said solenoid is de-energized.
 2. The punch press in accordance with claim 1 wherein said solenoid is contained within a housing and wherein there is further included means for coupling said housing directly to said leader pins.
 3. The punch press in accordance with claim 1 wherein there is further included bushing means in said tool holder for slidably receiving said leader pins.
 4. The punch press in accordance with claim 1 wherein there is further included resilient bumper means on said leader pins for cushioning said punch holder at the end of its stroke when said solenoid is energized.
 5. The punch press in accordance with claim 1 wherein there is further included resilient bumper means on said leader pins for cushioning said punch holder at the end of its stroke when said solenoid is de-energized.
 6. The punch press in accordance with claim 1 wherein said wound solenoid coil comprises a length of aluminum foil and there is further included a layer of electrical insulation between adjacent turns of said winding.
 7. The punch press in accordance with claim 1 wherein said tool holder includes a concave seat, said armature having a spherical end portion in engagement with said seat.
 8. The punch press in accordance with claim 2 wherein there is further included resilient bumper means intermediate said armature and said housing.
 9. The punch press in accordance with claim 2 wherein said means for moving said armature comprises spring means extending between said housing and said armature.
 10. The punch press in accordance with claim 9 wherein there is further included a pin extending through said armature, one end of said spring means being coupled to said pin, said housing including a cap and means for securing said cap to said housing, the other end of said spring means being secured to said cap.
 11. The punch press in accordance with claim 2 wherein said solenoid coil is encapsulated in an epoxy resin.
 12. The punch press in accordance with claim 11 wherein said encapsulated coil is keyed to said housing. 